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Stopwatch and Timer Calibrations (2009 edition)



Jeff C. Gust, Robert M. Graham, Michael A. Lombardi


Stopwatch and timer calibrations are perhaps the most common calibrations performed in the field of time and frequency metrology. Hundreds of United States laboratories calibrate many thousands of timing devices annually to meet legal and organizational metrology requirements. However, until the first publication of this guide (in 2004), no definitive text had existed on the subject. This revised NIST Recommended Practice Guide fills a gap in the metrology literature. It assists the working metrologist or calibration technician by describing the types of stopwatches and timers that require calibration, the specifications and tolerances of these devices, the methods used to calibrate them, and the estimated measurement uncertainties for each calibration method. It also discusses the process of establishing measurement traceability back to national and international standards.
Special Publication (NIST SP) - 960-12
Report Number


calibration, frequency, legal metrology, time interval, traceability


Gust, J. , Graham, R. and Lombardi, M. (2009), Stopwatch and Timer Calibrations (2009 edition), Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed July 20, 2024)


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Created January 28, 2009, Updated January 27, 2020